Induction brass annealer redux

[David101]

I think you will find the two wire plug goes too the shunt. The red and black on the 3 wire are for power and the third wire is a ground reference

 

[McHaggis]

Check out post 1047 by SGK. That should help.

 

[McHaggis]

Page 53.

 

[270guy]

I think you will find the two wire plug goes too the shunt. The red and black on the 3 wire are for power and the third wire is a ground reference

Thanks David. Here are some pics of my meter. To be 100% clear (bear with me please), Large black wire to the 48V power supply negative side into the shunt, large red wire to the 48V power supply positve (in to the contactor). Both on the 2 wire plug to the meter. Small red and black wires (3 wire plug), to 12V power supply (positive and negative). Small yellow wire (3 wire plug), to the opposite side of the shunt, to the large black wire. And then a separate wire, to complete the negative side of the 48V power supply, to the contactor.
Hopefully that is clear, on how I think the meter is added to the circuit. Please let me know if that is wrong. Thanks Brendon

 

[270guy]

Page 53.

Brilliant! Thanks McHaggis.
ITS ALIVE!!!! Only time for a few trial runs, with some 270 brass.

Thanks for helping me out, and going to the trouble of finding that post. Guess it time to heat up some more brass tomorrow!
cheers
Brendon

 

[oliverpsmile]

I am still waiting for my 2400 watt power supply ($65+$5 shipping) but went ahead and tested with my 500 watt supply.

Dima Prok

Would you mind to provide some more info (supplier, manufacturer etc) for the above mentioned Power Supplies. I liked the readings of the 500 watts.

Thanks

 

[McHaggis]

Brilliant! Thanks McHaggis.
ITS ALIVE!!!! Only time for a few trial runs, with some 270 brass.

Thanks for helping me out, and going to the trouble of finding that post. Guess it time to heat up some more brass tomorrow!
cheers
Brendon

All good. I doubt there are many kiwi builds of this so I’m glad I could help.
Don’t burn your fingers!

 

[SGK]

Hey I’m a kiwi! Just one that’s flown to foreign shores.

 

[270guy]

All good. I doubt there are many kiwi builds of this so I’m glad I could help.
Don’t burn your fingers!

...and David101 (although I think he is from the West Island ), also helped. Too late, I did pick up a piece of brass that had only been in the tray a little bit, to look at it. Won't do that again. Have had a great time boring the family and anyone who made the mistake to listen, telling them about thinking about and actually building this. And more fun putting it together.
cheers
Brendon

 

[Dima Prok]

Dima Prok

Would you mind to provide some more info (supplier, manufacturer etc) for the above mentioned Power Supplies. I liked the readings of the 500 watts.

Thanks

Oliver,

The 500 power supply I am using I originally bought from ebay for $50 shipped, but same power supply can be bought from Banggood for about $40. Just be careful with these guys. The 1800 watt board they sent me (cost $50) came with banged up, with heatsink bent in and studs that hold it to PCB broken. It works but I am working on trying to figure out while does PCB reach over 320F under capacitors closest to coil. What I didn't understand from the 1st page of this forum it was repeated over and over about "don't exceed your 11-12 amps or bad things will happen and this is with 2x more expensive Mean Well power supply and several people actually went to spend $170 on current controlled power supply, well let me tell you I was annealing metal parts with my little 500 watt power supply that's rated for 10 amps but actually pushes 11.8A and nothing happened to my power supply! Couple days ago I did 5 min straight tempering on steel hollow punch at 51.5V and watched the voltage dip in to 30+V because it was trying to pull too much current and nothing happened to my cheap power supply, it has fan which kicks in automatically and the size of it is actually quite compact. I figured I am going to crank it up to full 51.5V and that should make my anneals 3 seconds or less. if I was able to stress it for 5 minutes straight, surely it can handle 3 seconds of burst current for brass casings.
https://www.banggood.com/Switching-...-p-1115463.html?rmmds=search&cur_warehouse=CN P.S. I just got my 2400 watt power from them for about $70, the only drawback it runs on 220V (240 in US) but that's 48V 50A for my melting brass/copper/aluminum/zinc experiments.

 

[David101]

The 500W may be a bit small. I would stick with the recommend 750W or greater. It gives you just a bit more current if needed and although the duty cycle is not great with these machines. I think the Chinese supplies are really rated at 80% capacity. No need to go way overboard either as you will most likely never need the extra power.

@Dima Prok I am not a believer in trying to get the job done as quick as possible my reasoning is that to get it done quickly the rate of change in temperature is a steeper curve. Although you can very precisely set the time in the timer you cannot very precisely measure the temperature. Especially if it is changing very quickly. I tend to think there is more chance of overheating the brass and more uneven heating of the brass. With perhaps the neck rim going to a much greater temperature than the shoulder.

If it is heated a little more slowly and we are only talking seconds or tenths of seconds then more conduction of heat can occur in the part being heated and a more even temperature obtained.

All that is just my opinion I have no measurement to back up any of it. A good thermal video recorder would be needed to really tell what is happening.

 

[Dima Prok]

The 500W may be a bit small. I would stick with the recommend 750W or greater. It gives you just a bit more current if needed and although the duty cycle is not great with these machines. I think the Chinese supplies are really rated at 80% capacity. No need to go way overboard either as you will most likely never need the extra power.

@Dima Prok I am not a believer in trying to get the job done as quick as possible my reasoning is that to get it done quickly the rate of change in temperature is a steeper curve. Although you can very precisely set the time in the timer you cannot very precisely measure the temperature. Especially if it is changing very quickly. I tend to think there is more chance of overheating the brass and more uneven heating of the brass. With perhaps the neck rim going to a much greater temperature than the shoulder.

If it is heated a little more slowly and we are only talking seconds or tenths of seconds then more conduction of heat can occur in the part being heated and a more even temperature obtained.

All that is just my opinion I have no measurement to back up any of it. A good thermal video recorder would be needed to really tell what is happening.

My power supply even though is advertised as 500W produces about 600W (51.5V @ 11.7A) I agree with your points, I believe that there should be a balance between waiting too long and uneven super fast anneal, in my experiments I saw tempilaq melt pretty clearly and visibly going down shoulder I was only using 34.5V at 11.7A max and it took 4 seconds maybe 4.5, my digital relay timer arrived from eBay so now it's the matter of figuring out how to connect it program it and find exact time needed but I might go back and buy/fix my 1000 watt board. I don't like the idle temps so high on 1800W board, at least on 1000 watt board it's easier to cover the base with heatsinks. I might even add water cooling to PCB since I have several water blocks from old CPUs I upgraded. I even have a long copper waterblock from video card as well as couple radiators.

P.S. The original build was based on 600W PS, I think it's enough. The main thing, they are so dirt cheap. $39 power supply, $31 induction board, $25 timer, $5 SSR relay, $4 pump, $3.50 copper tubing on ebay, I got mine from recycle place for a dollar or 2, free selenoid pulled from laser printer, also fuse holders and fuses. Free tubing pulled from from old oxygen tank. $5 case with build in fan that houses CNC controller from recycle place. Got bunch of heatsinks salvaged but had to spend $10 on thermal non conductive glue.

 

[David101]

With the water cooled stuff already there using some computer water blocks is a good idea. I used some normal thermal paste in the middle of a heatsink and some Allridite adhesive on the edge. It worked well just makes board repair a bit more difficult if needed.

@Dima Prok the website that you posted about http://www.neon-john.com/Induction/Roy/Roy.htm
had some information on possible upgrades to the circuit re driving the mosfets harder (using smaller resistors) which ties in with what was posted by another guy that looked at the waveform diriving the mosfets and found they turned on and off better at the higher voltages 36V-48V.

You have done well with making it so cheaply. As you found the boards do get banged up in transport mostly because of bad packaging and poor construction.

I would really highly recommend everyone look closely at all the solder joints before turning on and if in doubt just re-solder the joint esp on the parts that have weight to them the inductors and mosfets with the heatsinks. Highly likely to have hairline cracks in the joints (cold solder joints) just reheat and perhaps add a bit of solder.

 

[YoungSC]

Hi All,

I'm reading through this thread and am up to page 30.

I can't see an available SainSmart induction heater on eBay or Amazon. I did some searches on this thread trying not to be lazy, but nothing jumped out discussing reliable alternatives. Am I missing something? Has this been discussed? Is there another option?

Thanks.

 

[Gina1]

Hi All,

I'm reading through this thread and am up to page 30.

I can't see an available SainSmart induction heater on eBay or Amazon. I did some searches on this thread trying not to be lazy, but nothing jumped out discussing reliable alternatives. Am I missing something? Has this been discussed? Is there another option?

Thanks.

I checked and it is still available on Amazon. Prices are all over the place. The unit by SainSmart is now $54.95 (??) But if you look at "what other customers bought" futher down the page you will find the same unit at lower prices ??

The following is a link to one of them.

Gina

https://www.amazon.com/dp/B07DWV6Z12/?tag=accuratescom-20

 

[YoungSC]

Thanks mate, so same item, different name.

 

[Dima Prok]

I checked and it is still available on Amazon. Prices are all over the place. The unit by SainSmart is now $54.95 (??) But if you look at "what other customers bought" futher down the page you will find the same unit at lower prices ??

The following is a link to one of them.

Gina

https://www.amazon.com/dp/B07DWV6Z12/?tag=accuratescom-20

This link shows $36.99 for me, but if you have patience you can save $9+ dollars and order on ebay https://www.ebay.com/itm/1000W-ZVS-...Module-Flyback-Driver-Heater-hot/172932050124

 

[David101]

This is the best quality one I have seen and from a reliable seller cheap also.

https://www.ebay.com.au/itm/New-Gee...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

$18 AUD

 

[YoungSC]

Thanks Gents

 

[McHaggis]

...and David101 (although I think he is from the West Island ), also helped. Too late, I did pick up a piece of brass that had only been in the tray a little bit, to look at it. Won't do that again. Have had a great time boring the family and anyone who made the mistake to listen, telling them about thinking about and actually building this. And more fun putting it together.
cheers
Brendon

Hahaha. I did the same thing. And yes family etc just don’t get it and are at best pretending to be politely interested even tho they have no idea what we’re talking about. Thank god for forums!